$\dfrac{2}{5} \div \dfrac{8}{5} = {?}$
Dividing by a fraction is the same as multiplying by the reciprocal of the fraction. The reciprocal of $\dfrac{8}{5}$ is $\dfrac{5}{8}$. Therefore: $ \dfrac{2}{5} \div \dfrac{8}{5} = \dfrac{2}{5} \times \dfrac{5}{8} $ $ \phantom{\dfrac{2}{5} \times \dfrac{5}{8}} = \dfrac{2 \times 5}{5 \times 8} $ $ \phantom{\dfrac{2}{5} \times \dfrac{5}{8}} = \dfrac{10}{40} $ $ \phantom{\dfrac{8}{3} \times \dfrac{3}{5}} = \dfrac{1}{4} $